Pollination Services

Insect pollinators are essential for food production. They improve the yield and quality of many crops. Unfortunately, pollinator populations are under threat from land-use change, disease, climate change, and agrochemicals. Use Penn State Extension’s Resources to learn more about pollination services, the benefits for crops, and pollinators’ roles in orchards and vegetable production.

Pollination Services and Crop Benefits

We rely on animal pollinators for food security and food diversity. Pollinator numbers are declining, which is likely to impact the production and the cost of many crops. There are many causes for pollinator decline. Parasitic mites, for example, have had an impact on bee colonies and their hives.

Traditionally, mother nature and her native pollinators would have provided pollination. More recently, however, we’ve been turning to pollination services. Wild and managed non-honey bee species have been supplementing honey bee pollination for several years now. Practices such as the use of flowering cover crops can also help boost pollinator numbers.

Pollinators in Orchards

We tend to think of honey bees as being the primary pollinators, particularly in orchards. There are, however, several other pollinators responsible for cross-pollination in apple and cherry orchards. They include:

• Pollen bees: Pennsylvania fruit growers have been relying on these for more than five years, and there has been no noticeable loss in the quality of the fruit or the yield.
• Wild bees: Research is now showing that wild bees also have a considerable contribution to make in fruit tree pollination.
• Mason bees: Two species of mason bees are currently used for tree fruit pollination, although it is limited.

When you plant fruit trees in your garden, always be aware of their pollination characteristics and the effective pollination period. Some self-fertile plants will set fruit with their own pollen, but production will be much higher is you plant two or more varieties close to each other.

Pollinators and Small Fruits

Pollinators have a critical role to play in the production of small fruits. Blueberries, a high-value crop in Pennsylvania, for example, require pollination by bees. Self-pollination, via gravity or wind, is not possible because of the shape of the flowers. Strawberries require complete pollination in order to develop larger, more symmetrical fruits.

Pollinators and Vegetable Crops

We can group vegetable crops into four categories according to the way they pollinate.

• Self-pollinizers: Have flowers that can only receive their own pollen. Examples include bush, pole, and lima beans, tomatoes, chicory, and endive.
• Form seeds only with pollen from an unrelated plant: This group includes radish and cabbage.
• Cross pollinated vegetables: may set seed from their own pollen or pollen received from another plant. Examples include carrots, celery, corn, cucumbers, and onions.
• The plant has both male and female parts: Only when male plants furnish pollen will a seed form. Examples include pumpkin, spinach, asparagus, and some hybrid cucumbers.